The US national team might have gotten outclassed in the attacking third during their defeat to Germany in closing out group play last week, but if forward Chris Wondolowski is to be believed, the underdog Americans won’t go into the knockout round of the 2014 World Cup settling for defensive-minded soccer.

“I feel that [attacking] is where our mindset is right now,” Wondolowski told Bay Area reporters via phone Monday night from Salvador, where the Americans will face Group H winners Belgium on Tuesday in a Round of 16 match (4 pm ET, ESPN/Univision in US, CBC in Canada). “Each team dictates a different game plan, and I think the one we’re crafting up right now is a special one. It’s a bit more attack-oriented, and I think that we need to catch them, especially on the counterattacks. . . . I think that can happen.”

With no clean sheets in three tries, it’s likely the US will need to find goals against a Belgian side that allowed only one tally in sweeping through Algeria, Russia and South Korea. They also need to hone their fine edge after coming out in somewhat dull fashion against Germany -- something the San Jose Earthquakes’ captain ascribed to the fact that a victory was not a necessity.

“Going into that game, there were a lot of scenarios where, if we didn’t get a win, we could still advance,” Wondolowski said. “Sometimes that creeps into your mind. We know going in against Belgium, there is no other outcome that can happen. We have to win. Whether it takes 90 minutes, 120 or penalties, we have to win. And that’s all we’re concentrating on.”

Wondolowski sounded a guarded note when talking about injured US striker Jozy Altidore, who left early with a hamstring problem in the Americans’ first match, an eventual 2-1 win against Ghana. Altidore hasn’t played since but is expected to be available Tuesday.

For how long is anybody guess, however.

“It’s definitely tough for anyone to play 90 minutes, especially in this heat and humidity,” Wondolowski said. “It should be interesting to see how long [Altidore] can go and see how much he has in the tank. He’s been working very hard to get back and to get healthy again, so hopefully he can go out and help us any way he can.”

Of course, no team is fully healthy at this point, and the Belgians are a case in point. Defender Thomas Vermaelen has been ruled out, and captain Vincent Kompany’s status is still a mystery after he sat out the group play finale with a strained groin.

To Wondolowski, the physical state of a club takes a back seat to something more important.

“[Successful teams haven’t] necessarily been the ones that have been physically strong, it’s the ones that have been mentally strong throughout this tournament,” Wondolowski said. “The ones that keep driving through the 90th minute. The ones that have done the preparation. We feel that we are very well prepared. . . .

“It’s been a great experience. Just to be a part of this team, it’s truly special. I think that we have something special in this locker room. And when you have that, I think you can achieve great things.”